1. Field of the Invention
The invention relates to a binocular telescope containing a camera.
2. Description of the Related Art
As is well known, a binocular telescope is used for watching sports, wild birds, and so on. When using such a binocular telescope, it is often the case that the user sees something that he or she would like to photograph. Typically, he or she will fail to photograph the desired scene because he or she must exchange a camera for the binocular telescope, and during this time the chance is lost. For this reason, a binocular telescope containing a camera is proposed, whereby a photograph can be taken immediately by using the camera contained in the binocular telescope while continuing the observation through the binocular telescope.
For example, Japanese Laid-Open Utility Model Publication (KOKAI) No. 6-2330 discloses a combination of a binocular telescope and a camera, in which the camera is simply mounted on the binocular telescope. Of course, the binocular telescope includes a pair of telescopic lens systems, and the camera includes a photographing lens system. While an object is observed through the pair of telescopic lens systems, the observed object can be photographed by the camera. This binocular telescope with the camera is bulky, and is not so easy to handle, because the camera is merely added to the binocular telescope.
Also, there is known another type of binocular telescope containing a camera, in which an objective lens system, included in one of both the telescopic lens systems, is utilized as a part of the photographing lens system.
In particular, each of the telescopic lens systems includes an objective lens system, an erecting prism system, and an ocular lens system. A half mirror is incorporated in one of the telescopic lens systems so as to be disposed between the objective lens system and the erecting lens system to define an angle of 45° with respect to the optical axis of the telescopic lens system concerned. A light beam, made incident on the objective lens system, is divided into two parts by the half mirror. Namely, a part of the light beam passes through the half mirror toward the ocular lens system, and the remaining part of the light beam is reflected by the half mirror so as to be introduced in the photographing lens system.
Due to this arrangement, this type of binocular telescope with the camera may be more compacted in comparison to the binocular telescope with the camera, as disclosed in the Publication (KOKAI) No. 6-2330. Nevertheless, it is disadvantageous in that an amount of the light beam to be made incident on the photographing lens system is diminished.
When a camera, especially, a digital camera, is combined with a binocular telescope, it is necessary to incorporate various electronic devices in the binocular telescope with the camera. Thus, batteries must be loaded in the binocular telescope with the camera before the various electronic devices can be electrically energized. In this case, it is very significant where the batteries are placed in the binocular telescope with the camera, due to a relatively large weight of the batteries.
In particular, if the binocular telescope with the camera exhibits an unbalanced weight distribution, it is difficult to stably hold the binocular telescope with the camera in a user's hands for a long time, and the user becomes susceptible to fatigue due to the unbalanced weight distribution. Also, the unbalanced weight balance results in a camera-shake. Accordingly, the location for the relatively heavy batteries should be taken into consideration, before a well-balanced weight distribution can be obtained for the binocular telescope with the camera.